Description:

Model Name: Micro ATMEGA32U4-AU
Voltage: 3.3V
Frequency: 8MHz
Interface: Micro USB
Application: for Arduino
Operating temperature: -40°C to +85°C

The Pro Micro is similar to the Pro Mini except with an ATmega32U4 on board.
The USB transceiver inside the 32U4 allows us to add USB connectivity on-board and do away with bulky external USB interface.
4 channels of 10-bit ADC, 5 PWM pins, 12 DIOs as well as hardware serial connections Rx and Tx.
Running at 8MHz and 3.3V